Rubbing Ghost Mura is a very serious quality problem in the existing process for a thin film transistor (TFT). It not only severely influences the image quality of products and the yield thereof, but also results in a low detection rate for inferior products, which easily gives rise to missed detection and causes huge waste of resources and materials in the back end accompanied by serious quality problems. The root cause for the problem of poor quality can be construed as follows. Since edges of a glass substrate have binding lines, during a rubbing process, when the rubbing proceeds to a connection position, friction cloth will generate an electrostatic difference as it contacts different surface mediums (including ITO, PVX and alignment film), and thus the fabric direction or the like of the cloth will be changed. In this case, unfavorable alignment abnormality will occur at the end of the rubbing, which is called Ghost Mura.